docs: def is_url_allowed(url):
      """ Return ``True`` if ``url`` is not in ``blacklist``.
  
      :rtype: bool
  
      """
      blacklist = [
          r'\.ttf', r'\.woff', r'fonts\.googleapis\.com', r'\.png', r'\.jpe?g', r'\.gif',
          r'\.svg'
      ]
  
      for ft in blacklist:
          if re.search(ft, url):
              return False
  
      return True